Merck, I4269-50UG, Interleukin-4 human

Interleukin-4 (IL-4) is a pleiotropic cytokine that regulates diverse T and B cell responses including differentiation of naive T cells into the TH2 phenotype, promoting B cell proliferation, antibody isotype switching, and expression of other TH2 cytokines including IL-5 and IL-9.1,2 IL-4 plays a critical role in the development of allergic inflammation and asthma.³ IL-4 binds to two distinct receptors; the type I receptor, a heterodimer consisting of the IL-4Rα chain and the common gamma chain, γc, and the type II receptor, a heterodimer of IL-4Rα and IL-13Rα1.⁴ Naturally occurring IL-4 has a molecular mass of 12-20 kDa. Recombinant human IL-4 is a 14.9 kDa protein containing 129 amino acid residues. Human and mouse IL-4 share a 50% amino acid sequence homology, but their biological actions are species-specific.⁵